1. Field of the Invention
The present invention relates to assistive hearing devices. More specifically, the present invention relates to a hearing aid mounted internally to an ear.
2. Description of the Related Art
Hearing devices are well known and typically include a microphone, an amplifier and a speaker. Typically, the microphone receives a sound wave and converts the wave into an electrical signal, the amplifier amplifies the electrical signal, and the speaker converts the amplified signal into amplified sound waves that impart vibrations to the tympanic membrane or ear drum in the ear. Common hearing aids are mounted outside the ear canal, particularly around the outer ear. The externally mounted hearing aid has the advantage of accessibility to change batteries and to adjust the volume of sound. However, many users find such externally mounted hearing aides relatively bulky and objectionable for cosmetic reasons.
An alternative to externally mounted hearing aides are internally mounted hearing aids disposed in an ear canal of a user. Such internally mounted hearing aides offer better cosmetic appearance, but have disadvantages as well. For instance, the typical internally mounted hearing aid blocks the majority, if not all, of the ear canal diameter. Such blockage can cause the body of the user to produce an excessive amount of ear wax in the ear canal and can cause ear infections. Further, the blocking of the ear canal obstructs the natural transmission of sound waves through the ear canal that impact the tympanic membrane. Unless a user is totally hearing impaired, any ability of the tympanic membrane to register the natural occurring sound waves is reduced or eliminated. Thus, the user is substantially dependent upon the sound fidelity of the hearing aid. Still further, the typical internally mounted hearing aids may still be somewhat visible in the ear canal.
Some hearing systems deliver audio information to the ear through electromagnetic transducers. A microphone and amplifier transmit an electronic signal to a transducer that converts the electronic signal into vibrations. The vibrations vibrate the tympanic membrane or parts of the middle ear that transmit the sound impulses without reconverting to audio sound waves. A separate magnet can be remotely mounted at or near the tympanic membrane. The interaction between the magnetic fields of the transducer receiving the electronic signal and the magnet mounted at or near the tympanic membrane causes the magnet to vibrate and thus mechanically transmits the sound through the vibration to the ear. Typically, however, the remainder of the hearing aid is inserted into the ear canal or on the outer ear and can cause the problems discussed above. Still further, the transducers and/or magnets of the hearing aids are mounted in a relatively invasive procedure. For instance, one contact transducer having a magnet is installed by drilling through the mastoid bone, cutting through the tympanic membrane, microscopically drilling a bone structure and screwing the magnet to the malleus of the ossicular chain in the middle ear. Such procedures may be painful, expensive, and can have serious complications.
As described above, there are various types of hearing aids that are used to amplify and transmit sound waves to the hearing center of the brain resulting in the perception of sound. However, the present types of hearing aids do not selectively suppress sound waves generated by background noise and excessively loud noises while simultaneously transmitting normal speech and other desirable acoustic signals. Noise suppression could be used by astronauts on long duration missions such as the International Space Station or a Mars mission that want to selectively suppress background noise created by rotating machinery, air handling systems, and environmental control systems while still allowing the astronaut to hear the sound waves generated by other astronauts and other desirable acoustic signals. Further, the present types of hearing aides do not allow a user to amplify predetermined frequencies more than other frequencies, thereby allowing for super normal hearing of selective frequencies. Amplification of selective frequencies could be used in a military operation, wherein sound waves generated by enemy combatants could be amplified and sent to the hearing center of the brain while all other sound waves are transmitted in a normal manner. Additionally, the present types of hearing aids do not allow a user to receive signals or sound waves that are not audible to a normal person, such as in covert communication.
Therefore, there remains a need for a relatively compact hearing aid that can be inserted in the ear canal and/or through the tympanic membrane which can be used to selectively suppress sound waves generated by background noise and excessively loud noises while simultaneously hearing normal speech and other desirable acoustic signals. There is a further need for a relatively compact hearing aid which can be used to amplify predetermined frequencies greater than other frequencies, thereby allowing for super normal hearing of the predetermined frequencies. There is yet a further need for a relatively compact hearing aid which can be used to receive signals or sound waves that are not audible to a normal person.